Effects of Different Therapeutic Radiation Doses on the Development of Neural Tube Defects in Chick Embryos and the Correlation with Bone Morphogenetic Protein 4 and 7 Expression Levels.

AIM: To investigate the effects of different therapeutic radiation doses on the prevalence of neural tube defects (NTDs) in chick embryos and bone morphogenetic protein (BMP) 4 and BMP7 expression levels. MATERIAL AND METHODS: The chick embryos (n=143) were derived from fertile, specific pathogen-free eggs of domestic fowl. The presence of NTDs was analyzed using a stereomicroscope, and BMP4 and BMP7 expression levels were assessed by immunohistochemical staining. The chick embryos were divided into five groups: control (no radiation exposure) (n=23), exposure to thorax computerized tomography (CT) (n=30); exposure to abdominopelvic CT (n=30), exposure to cranium CT (n=30), and exposure to brain perfusion CT (n=30). RESULTS: The prevalence of NTDs and BMP4 and BMP7 expression levels in the different groups were compared. In the cranium CT dose group, both the NTD prevalence (20%, p=0.002) and BMP7 (p=0.031) expression levels were significantly higher than those in the other groups. However, none of the medical doses of irradiation altered BMP4 expression levels (p=0.242). No NTDs were detected in the thorax CT and abdominopelvic CT groups. CONCLUSION: Exposure to irradiation at cranium CT doses may induce the development of NTDs and increase BMP7 expression. Dose radiation exposure using thorax CT and abdominopelvic CT protocols does not appear to induce NTDs.

The effect of magnetic resonance imaging on neural tube development in an early chicken embryo model.

PURPOSE: We aimed to determine whether varying the magnetic field during magnetic resonance imaging would affect the development of chicken embryos and neural tube defects. METHODS: Following incubation for 24 h, we exposed chicken embryos to varying magnetic fields for 10 min to assess the impact on development. Three magnetic resonance imaging devices were used, and the eggs were divided into four groups: group 1 is exposed to 1 T, group 2 is exposed to 1.5 T, group 3 is exposed to 3 T, and group 4, control group, was not exposed to magnetic field. After MRI exposure, all embryos were again put inside incubator to complete 48 h. "The new technique" was used to open eggs, a stereomicroscope was used for the examination of magnified external morphology, and each embryo was examined according to the Hamburger and Hamilton chicken embryo stages. Embryos who had delayed stages of development are considered growth retarded. Growth retardation criteria do not include small for stage. RESULTS: Compared with embryos not exposed to a magnetic field, there was a statistically significant increase in the incidence of neural tube closure defects and growth retardation in the embryos exposed to magnetic fields (p < 0.05). However, although the incidence of neural tube closure defects was expected to increase as exposure (tesla level) increased, we found a higher rate of defects in the 1.5-T group compared with the 3-T group. By contrast, the highest incidence of growth retardation was in the 3-T group, which was consistent with our expectation that growth retardation would be more likely as tesla level increased. CONCLUSIONS: We therefore conclude that the use of magnetic resonance imaging as a diagnostic tool can result in midline closure defects and growth retardation in chicken embryos. We hypothesize that this may also be true for human embryos exposed to MRI. If a pregnant individual is to take an MRI scan, as for lumbar disc disease or any other any other reason, our results indicate that consideration should be given to an avoidance of MRI during pregnancy.

Evaluation of the effects of mobile phones on the neural tube development of chick embryos.

AIM: The objective of this study is to examine the effects of radiation of mobile phones on developing neural tissue of chick embryos. MATERIAL AND METHODS: There were 4 study groups. All Groups were placed in equal distance, from the mobile phones. Serial sections were taken from each Group to study the neural tube segments. RESULTS: The TUNEL results were statistically significant (p < 0.001) at 30 and 48 hours in the third Group. We found low Bcl-2 levels partly in Group 4 and increased activity in Group 3. Caspase-3 was negative in the 48 and 72 hours in the Control Group, had moderate activity in the third Group 3, weak activity in the 48 hour, and was negative in the 72 hour in other groups. Caspase-9 immunoreactivity was weak in Group 1, 2 and 3 at 30 hours and was negative in Group 1 and 4 at 48 and 72 hours. Caspase-9 activity in the third Group was weak in all three stages. CONCLUSION: Electromagnetic radiation emitted by mobile phones caused developmental delay in chick embryos in early period. This finding suggests that the use of mobile phones by pregnant women may pose risks.